1. Field of the Invention
The present invention relates to a light source. More specifically, the present invention discloses a flicker-less light source that is safe to humans, environmentally friendly, and possesses an extremely long lifetime.
2. Description of the Prior Art
Fluorescent lights are a commonly used light source. In a fluorescent light an electric current stimulates mercury atoms. The stimulation causes the mercury atoms to release ultraviolet photons which stimulate a phosphor. The stimulated phosphor then emits visible light photons.
Refer to FIG. 1, which is a drawing illustrating a conventional fluorescent light installation. As shown in FIG. 1, a conventional fluorescent light installation 100 consists of a sealed glass tube 110 containing a small amount of mercury and inert gas with a phosphor powder coating on the inside of the glass tube 110. An electrode 120 is situated on both ends of the sealed tube 110. A starter 150 allows current to flow to turn on the fluorescent tube 110.
When alternating current 130 is applied electrons migrate through the gas from one end of the tube 110 to the other. As a result the liquid mercury turns into a gas. Collisions between electrons, charged atoms, and mercury atoms cause the electrons to move to a higher energy level. After a short period of time the electrons will return to their original energy level and release light photons.
Electrons in mercury atoms release light photons in the ultraviolet wavelength range which are not visible to humans. In order to convert the ultraviolet light into visible light the phosphor coating is used to release photons of a lower energy.
While fairly effective, the conventional fluorescent light source has numerous disadvantages. One disadvantage is that it can take several seconds for the fluorescent light to start emitting light.
Another disadvantage is that it is difficult to maintain a stable flow of current through the gas which in some cases can cause the light tube to explode or can destroy other components in the circuit.
Refer again to FIG. 1. In order to control the current, a ballast 140 is used to slow down changes in the current by modulating the current at a low cycle rate. Unfortunately, this causes the light to flicker which is annoying and irritating.
Additionally, the ballast 140 can vibrate at a low frequency which is audible to humans and causes further irritation. Workers in environments using fluorescent light have filed complaints of headaches, eye strain, and general eye discomfort.
Furthermore, disposal of fluorescent light systems is problematic since some of the waste is hazardous. For example, some ballasts contain polychlorinated biphenyls (PCBs) or 2-ethylhexyl phathatlate (DEHP) which are carcinogens that can cause liver, skin, and reproductive disorders. Also, fluorescent light tubes contain a small quantity of mercury that can be harmful to the environment and to human health.
In order to properly dispose of the fluorescent light systems special care must be taken and special hazardous waste landfills must be used. This is not only expensive and potentially dangerous but also damaging to the environment.
Therefore, there is need for an improved light source to replace fluorescent light systems that is economical, effective, and safe to humans and the environment.